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Quantitation of residual hydrogen peroxide (H2O2) and evaluation of the impact on product stability is necessary as unwanted H2O2 can potentially be introduced during the manufacturing of pharmaceuticals, biologics, and vaccines. A sensitive and convenient microplate-based method with fluorescence detection for H2O2 quantitation was recently reported (Towne et al., 2004, Anal Biochem 334: 290–296). This method was found to be highly robust and reproducible, with a level of detection of 0.015 ppm and a level of quantitation of 0.025 ppm (in water). The relatively small sample requirements and amenability for automation make this assay an attractive tool for detecting residual H2O2 levels. Without additional manipulation, the assay can be conducted on heterogeneous solutions with significant degree of turbidity, such as the presence of suspensions or aluminum-containing adjuvants. The quantitation of H2O2 and its decomposition kinetics was also studied in presence of two common vaccine preservatives (thimerosal and phenol) and eight commonly used excipients (polyols). Over time, there is a distinct, temperature dependent decrease in H2O2 recovered in thimerosal and phenol containing samples versus non-preservative containing controls. Based on the half-life of spiked H2O2, the decay rates in eight polyols tested were found to be: ribose > sucrose > (glycerol, glucose, lactose, mannitol, sorbitol, and xylose). © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:3987–3996, 2009 [ABSTRACT FROM AUTHOR]

Abstract: The use of multi-factor statistical experimental design methodology minimized the vaccine material and laboratory resources required for optimization and validation of an HPLC assay for quantitation of deploymerized and total PRP. Components of the assay selected for optimization were adjuvant dissolution, ultracentrifuge conditions including ultracentrifuge model, sample diluent, mobile phase and column oven temperature. Previous experience has shown these components of the assay to be most troublesome and therefore required optimization prior to validation. Specificity, linearity, precision, accuracy and ruggedness were confirmed through a validation of the optimized assay. The validation also established the assay to be stability indicating, by showing that changes to the integrity of the PRP-OMPC conjugate could be detected. [Copyright &y& Elsevier]

Abstract: A sensitive and reproducible method to determine the in vitro infectious potency of a pentavalent reassortant rotavirus vaccine (RotaTeq®) has been developed as an alternative to classical potency assays. Potency was determined based on cell-based viral replication followed by quantitative reverse-transcription polymerase chain reaction (RT-QPCR) analysis. In the assay, confluent Vero cell monolayers in 96-well plates were inoculated with serial dilutions of test samples, a pentavalent reassortant rotavirus reference standard and assay controls, followed by incubation for 24h. The cells were lysed with a Triton X-100 solution and the lysates assayed by RT-QPCR to quantitate viral nucleic acid produced during replication. The RT-QPCR utilizes primer/probe sets specific to each virus reassortant and the potencies of each sample were determined relative to the reference standard. This assay, hereafter referred to as the Multivalent QPCR-Based Potency Assay (M-QPA), permits the specific quantitation of each individual reassortant virus in the presence of the other four reassortant viruses. In addition, the assay was demonstrated to be concordant with a traditional method (plaque assay) for the quantitation of infectious virus particles. It is anticipated that assays of this type will become a valuable tool in the assignment of potency values and in the monitoring of stability of live virus vaccines. [Copyright &y& Elsevier]